Reproducing pictures by means of catalysis.



UNITED STATES Patented January 10, 1905.

PATENT OFFICE.

REPRODUCING PICTURES BY MEANS OF CATALYSIS.

SPECIFICATION forming part of Letters Patent No. 779,797, dated January10, 1905. Application filed December 9, 1903. Serial No. 184,481.

' To all w/com it may concern.-

ducing pictures by means of catalytic action.

The invention consists of the process of reproducing pictures whichcomprises the steps of bringing a catalytic agent into contact with onefactor of a coagulant of glutinous matter, bringing portions of saidfactor not catalytically affected into reaction with the other factor ofsaid coagulant, and subjecting glutinous matter to the action of thereaction product.

The improvementdepends on the fact that when the picture in hydrogenperoxid is brought into a solution of glutinous matter like glue,gum-arabic, gelatin, albumin, or the like, mixed with a substance orsubstances which reacts or react with hydrogen peroxid to form a productor products that coagulate glue, gum-arabic, gelatin, or albumin, it ispossible to produce such coagulation at those parts of the picture whichcontain hydrogen peroxid. There is thus obtained a picture of coagulatedglue or the like which when produced upon a differently-colored surfacewill be visible thereon or when produced upon a similarly-coloredsurface can be made visible, as hereinafter described.

By mixing the solution of the glutinous substance with a coloring-matterthe latter will be fixed on those parts where the glue has beencoagulated and a pigmented picture will be obtained. By using acatalytic negative there may be obtained in this manner a positive. Themethod may be used, however, for obtaining from a catalytic positive apositive picture, for there may be employed as substratum a coloredpaper,while the glue is mixed with a bright color. Furthermore,

the picture in glue or the like can be made visible by treatment withsuch substances as yield colors,with the glue, or with the material thatcauses the coagulation.

Both methods may be combined by adding coloring-matter to the gluesolution before coagulation and subsequently treating the picture withsubstances that yield colors with the coagulating material. There maythus be obtained mixed colors.

Example I: WVe pour a solution of hydrogen peroxid over a platinumprint. For instance, an ethereal solution may be used, which is obtainedby agitating an aqueous solution of hydrogen peroxid of thirty-three percent. strength with five times its volume of ether. At the partscontaining platinum, which, in this instance, is the catalytic agent,the hydrogen peroxid is destroyed by catalytic action with a speed whichis a function of the quantity of platinum existing at every part of theoriginal. The picture in hydrogen peroxid thus produced is brought intoa solution of Cologne glue, second grade, of ten per cent. strength, towhich for every one hundred (100) cubic centimeters has been addedfromten (10) to fifteen grains of Gassels brown and from seven (7) tofifteen (15) grains of a solution of ferrous ammonium sulfate of twentyper cent. strength. After the picture has remained for about a minute inthis solution it is washed with water, whereby the glue orcoloring-matter is washed away from those places on which-there was nohydrogen peroxid, so that a picture of colored coagulated glue remains.In this example the ferrous ammonium sulfate and hydrogen peroxid formtogether the coagulant of the glutinous matter. Each of said substancesconstitutes one factor of said coagulant.

Example 11: The picture in hydrogen peroxid prepared according toExample I is brought into a solution of glue of ten (10) per cent.strength, to every one hundred (100) cubic centimeters of which has beenadded from ten to twenty (10 to 20) grams of asolution of ferrousammonium sulfate of twenty (20) per cent. strength. The picture is keptin this solution for about aminute and is then washed with warm waterand brought into water saturatedv with gallic acid at the ordinarytemperature, whereby the picture is colored black. The ferrous ammoniumsulfate and hydrogen peroXid perform in this example the same functionsas in Example I.

Example III The colored picture produced according to Example I isbroughtinto asolution of gallic acid saturated at the ordinarytemperature. In the foregoing examples the proportions may be variedwithout varying the nature of the invention. Finally, a similar methodmay be applied for the multiplication of line-drawings, such as maps ormechanical drawings, by producing the invisible image on a surfaceprepared with glue, &c., and coloring-matter, on which the coagulationthen occurs at the requisite places. The above-described operations,therefore, are conducted in different order.

Example IV: A suitable paper for such multiplication is prepared bycoating paper with a solution of gelatin or glue in which a pigment issuspended. This paper is dried and is then ready for use. There isproduced thereon in the known manner by aid of catalysis a picture inhydrogen peroxid, and it is then brought into a solution of ferroussulfate of from ten (10) to twenty (20) per cent. strength, or asolution of some other ferrous salt. There is thus obtained a picture inwhich the glue has become insoluble. This picture is then developed bytreating it either with warm water or a solution of potassiumsulfocyanid. The parts where there is no hydrogen peroxid now swell upand by lightly passing a brush over the surface these parts may beremoved. In this example the ferrous ammonium sulfate and hydrodgenperoxid constitute the factors of the coagulant of the glutinous matter.

Now what we claim is 1. The herein-described process of producingpictures, which comprises the steps of bringing a catalytic agent intocontact with one factor of a coagulant of glutinous matter and bringingportions of said factor not catalytically aflected into reaction withthe other factor'of said coagulant and subjecting glutinous matter tothe action of the reaction product.

2. The herein-described process of producing pictures, which comprisesthe steps of bringing a catalytic agent into contact with one factor ofa coagulant of glutinous matter, bringing portions of said factor notcatalytically affected into reaction with the other factor of saidcoagulant, subjecting glutinous matter to the action of the reactionproduct, and coloring said glutinous matter.

3. The herein-described process of producing pictures, which comprisesthe steps of bringing a platinum print into contact with hydrogenperoxid, bringing portions of said hydrogen peroxid not catalyticallyaffected into contact with a ferrous salt, and subjecting gelatin to theaction of the reaction product.

4. The herein-described process of producing pictures, which comprisesthe steps of bringing a platinum print into contact with hydrogenperoxid, bringing portions of said hydrogen peroxid not catalyticallyaffected into contact with a ferrous salt, subjecting gelatin to theaction of the reaction product, and coloring the gelatin.

In testimony that we claim the foregoing as our invention we have signedour names in presence of two subscribing witnesses.

WILHELM OSTWALD. OSCAR GROS. Witnesses:

RUDOLPH FRICKE, B. H. WARNER, Jr.

